Merfolk
A Modern deck, by Austin Grady
4th place at a tournament in Dallas, Texas, United States on 2017-03-11

Maindeck:
12 Island

Artifacts
4 Aether Vial

Creatures
4 Cursecatcher
4 Harbinger of the Tides
4 Lord of Atlantis (Not currently legal in Modern)
4 Master of the Pearl Trident
4 Master of Waves
3 Merrow Reejerey
4 Silvergill Adept

Enchantments
4 Spreading Seas

Instants
2 Dismember
2 Spell Pierce

Legendary Creatures
2 Kira, Great Glass-Spinner

Lands
2 Ghost Quarter
3 Mutavault

Legendary Lands
1 Minamo, School at Water's Edge
1 Oboro, Palace in the Clouds

Sideboard:
3 Relic of Progenitus
4 Tidebinder Mage
2 Dispel
4 Hurkyl's Recall
2 Unified Will